Lucerne trees love to be pruned and pruning is a vital management strategy! Notice the wonderful dense, green bushy trees already pruned on the left, while the trees on the right are waiting to be pruned.
When lucerne trees are pruned, they burst into hundreds of new leaves all along the stems and branches. This forces the sapling to develop side branches and new leaves all along their stems and branches which creates a lovely full, bushy tree. If you look closely at the photo below, you will notice that several new branches have formed around the very short pruned stub of an old branch. By pruning one branch, this tree now will have 5 to 6 new branches!If left un-pruned, lucerne trees remain thin and spindly, growing into tall, but lanky trees with very little food available for grazing. Their branches tear and break easily when grazed. A pruned tree develops thick, sturdy stems and branches which do not break as the animals browse the leaves off the branches.
Prune your trees while their are still in their potting bags growing out to become 40cm tall. Simply nip the top growth tips off each sapling with your finger nails or use a hedge clipper for quicker pruning. Within a week or two, you will notice tiny leaves budding and forming all along their stems. These little saplings in their bags as seen in the photo below are ready for a light tip-pruning.Once transplanted, give your trees a few weeks to settle in and become established and then nip off all their growth tips and water well.
If your trees undergo any kind of stress, you may notice that their leaves may turn yellow and they may loose some of their leaves. Prune them quite well, taking off up to a third of the top of the tree and then rectify what might be causing the stress. This tree in the photo below was pruned just 30 days before!
Stress usually this has something to do with their roots or a water problem. Remember that lucerne trees hate to sit in wet, soggy soil, so don’t over-water! Likewise, drought will cause stress, so water your young trees regularly.
Stress may be caused by a lack of phosphates which works together with the rhizobia in the roots to fix nitrogen. A lack of phosphates may delay the trees’ roots from forming the nitrogen-fixing nodules which help the trees to become vital and healthy. Add half a cup of super phosphates mixed in the soil around the base of the stem and water regularly.
Insects could also cause damage and stress, Look for signs of snails, beetles or worms that may be nibbling your trees and deal with them as necessary. Mice may also cause stress and ring-bark at the base of the stems, This will usually cause the tree to die if they have eaten all the way around the bark. Place old irrigation pipes around your saplings if this is happening, and cut away and clear any long grasses and weeds around each tree where mice may find shelter.
By pruning off spindly, weak or failing branches, your trees have a far better chance of making a good recovery. Instead of pushing all their energy into stressed areas of the trees, they consolidate all their nutrition, food, water and energy into the main part of the tree, causing health and recovery.
To force your trees to create more foliage you automatically create more food. Pruning is a valuable resource as all the cuttings go into our chipper and yield amazing bulk, fibre and nutrition in the chipped food. Remember that your trees should be maintained at about 1 metre to 1.5 metre height so that your animals can graze everything at their height.
A healthy lucerne tree can’t help itself — it loves being pruned and will always sprout and bud soon after pruning.